SOME OBSERVATIONS AND EXPERIMENTS ON THE 



NATURAL AND ARTIFICIAL INCUBATION OF 



THE EGG OF THE COMMON FOWL. 



ALBERT C. EYCLESHVMER, 

 DEPARTMENT OF ANATOMY, ST. Louis UNIVERSITY. 



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Through a series of experiments on the developing chick, it 

 was found that frequently the variations in development were so 

 great that the value of the experiment was materially decreased. 

 An attempt was therefore made to obtain more data regarding 

 the following factors ; position of eggs, turning of eggs, cooling 

 of eggs, ventilation of eggs, moisture of eggs. 



Before detailing the observations and experiments it should be 

 emphasized that the eggs used were selected with much care. 

 They were largely from the variety of fowls known as " Ply- 

 mouth Rock." Especial care was taken to eliminate the effects 

 of disease, inbreeding, poor food, etc. No eggs were taken from 

 flocks in which there was not at least one cock for every ten 

 hens. All mottled, rough shelled and ill-shaped eggs were dis- 

 carded. Uniformity in size was next secured. The eggs were 

 then tested by transmitted sunlight and those in the same stages 

 of development selected. 



POSITION OF EGGS. 



That the position of the egg during incubation has an influence 

 on the development of the chick was shown by Dareste ('91, p. 

 171). It is also a well known fact among poultry raisers that 

 the position of the egg has a profound influence upon the growth 

 of the chick. All seem to agree that if the small end of the 

 egg is up, the head of the chick develops in this end, and as a 

 result, many chicks will either be deformed or fail to free them- 

 selves from the shell at the time of hatching. With these points 

 in mind, a series of observations was made with a view of deter- 

 mining just what position the eggs occupy during natural 

 incubation. 



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